A subpoena is a court order directing you to be present at the time and place stated. You will be personally served with your subpoena.
Bring the subpoena with you when you go to court because it will assist the court in processing the witness fees the law entitles you to receive. It also reminds you which court you are required to appear in and the exact time of your appearance. After receiving the subpoena, immediately call the Prosecuting Attorney's Office and ask for the deputy prosecutor assigned to the case; his or her name will appear on the subpoena.
This allows the deputy prosecutor an opportunity to discuss with you the facts of the case and the nature of the proceedings in which you will testify. Keep in mind that it is perfectly proper for the deputy prosecutor to discuss the case with you prior to the court date. In some cases, the deputy prosecutor may ask to meet with you.